Gauging the precise dangers these gadgets pose to our health could take years, so let's take precautions now.

Are cell phones having an impact on our brains?

The answer just got a little clearer when a new study in the Journal of the American Medical Association asserted unequivocally that, yes, cell phones change brain activity.

"This study shows that the human brain is sensitive to electromagnetic radiation coming out of cell phones," study author Nora Volkow told The Wall Street Journal. "Our finding does not tell us if this is harmful or not." Like a similar study backed by the World Health Organization last May, Volkow's study concluded it will take more research to ascertain just how harmful. Regardless, since four in five American adults already own one, it's urgent that we take precautions with cell phones.

Other researchers--especially those whom the cell phone industry didn't finance--have already concluded that cell-phone radiation poses risks, especially to children. Their smaller heads and thinner skulls can allow the radiation to penetrate deeper into their brains. For example:

• A 2009 analysis of 11 studies, published in Surgical Neurology, found that using cell phones for 10 years or more approximately doubles the risk of "a brain tumor on the same (ipsilateral) side of the head as that preferred for cell phone use."

• A 2009 analysis of 23 studies, published in the Journal of Clinical Oncology, found that people who used cell phones for 10 years or more had a 10-30 percent higher chance of developing cancer than those who rarely or never used them.

• Dr. Devra Davis's recently published book Disconnect: The Truth About Cell Phone Radiation, What the Industry Has Done to Hide It, and How to Protect Your Family, reports that not only do all studies of heavy cell phone users over a 10-year period find an increased risk of brain tumors, but scientists have warned against children using cell phones since as early as 2000.
So, what can be done?

Some governments already mandate cell-phone labeling as a precautionary step. Both the city of San Francisco and the Israeli government require that manufacturers display the specific absorption rate (SAR)--the amount of radiation absorbed by the body--on their cell phones. And the governments of Finland, Switzerland, Germany, the UK, Canada, and Russia have also issued warnings advising cell phone users, especially children, to use headsets to minimize exposure to radio-frequency radiation.

Unfortunately, there's not much movement on mandatory point-of-purchase SAR labeling in the United States. Companies like Motorola, T-Mobile, Blackberry, Kyocera, and Apple do include a few words of caution with their products already--in the fine print. If you page through your cell phone's owner's manual, you'll likely find buried precautionary language telling you to hold the phone at least "one inch away" from your head, or to always place the device inside a bag or holster to block radiation into your body.

Still, Davis said, consumers can't rely on cell phone companies for protection, since industry-funded studies often raise doubts about the independently funded studies that highlight radiation risks. She compares the cell-phone situation we face today to the lengthy struggle it took to prove tobacco's health detriments.
"In both of those situations, I noticed a pattern," Davis said. "First you'd have reports of harm to people. And then industry steps in to raise doubt of that harm."

Without a commitment from the companies that make and market cell phones for greater disclosure, or a legislative push for stronger regulation, what should consumers do?